1. Field of the Invention
The present invention relates to an interface module-mounted LSI package having a high-speed interface module for signal transmission for transmitting a high-speed signal to external wiring, and a heat sink for use in the package. The present invention also relates to an interface module with a heat sink.
2. Description of the Related Art
In recent years, a structure has been proposed, in which an interface module for transmitting/receiving an optical signal to/from an external device is directly mounted on an interposer equipped with a signal processing LSI (Hot Interconnects 9. Symposium on High Performance Interconnects, IEEE, pp. 31-35, 2001, and Nikkei Electronics No. 810, pp. 121-122, Dec. 3, 2001). In this structure, there is a great difference in height between the signal processing LSI and the interface module. Further, since the interface module has an optical connector on the side (rear side) facing in the direction of heat radiation by the signal processing LSI, the interface module and the signal processing LSI cannot radiate heat in the same direction. Therefore, it is difficult to efficiently cool the signal processing LSI and the interface module by one heat sink.
In another known structure, a heat sink of a package, comprising a number of LSI chips, is divided into a plurality of parts (Jpn. Pat. Appln. KOKAI Publication No. 10-173114). In the case of using such divided heat sinks, many parts are required and the assembly cost is high. Moreover, there is a high possibility of defective modes, such as imperfect assembly of the heat sinks (misalignment). Therefore, an increase in cost due to reduction in production or assembly yield is unavoidable.
As described above, according to the conventional art, in the case where the signal processing LSI and the optical interface module are mounted on one interposer, it is difficult to efficiently cool them by one heat sink. If a plurality of heat sinks are used, the production or assembly yield is lowered, resulting in increase in cost.